Vibration responsive mechanism for washing machines



VIBRATION RESPONSIVE MECHANISM FOR WASHING MACHINES Filed Feb. 16, 1954 June 16, 1959 J. F. ETHERINGTON 2 Sheets-Sheet 1 INVENTOR. J mm 1? ETHERms'ruN ETP.

ATTORNEY J1me .1959 J. F. ETHERINGTON 2,890,580

7 VIBRATION RESPONSIVE MECHANISM FOR WASHING MACHINES Filed Feb. 16, 1954 2 Sheets-Sheet 2 my mum IN V EN TOR.

JnHn F ETHERINGTEINY JITTUIPNEY United States Patent fitice Patented June 16, 1959 assignments, to The Murray Corporation of America, Detroit, Mich., a corporation of Delaware Application February 16, 1954, Serial No. 410,693

4 Claims. (Cl. 68-12) This invention relates to centrifugal extractor washing machines and more particularly to a control therefor adapted to act in response to severe vibration due to unusual unbalanced conditions. In washing machines of the type referred to in which centrifugal extraction takes place, there is always the extreme possibility that the wash load may be such as to position itself so as to create a severe unbalance, so that as the extractor increases its speed, vibration beyond the limits provided will result. Such vibration may take place if the speed of rotation increases and before the extractor passes through what is known as the critical speed. On the other hand, the severe vibration may develop after the extractor has passed through the critical speed as a result of a shifting of the load within the extractor. It is of course well known that in an accelerating and unbalanced extractor load, that as the critical speed is passed, such extractor tends from thereon to rotate about its center of gravity rather than its axis.

The present invention has been adapted to the type of washing machine described in a copending application, Serial No. 359,100, filed June 2, 1953, now Patent No. 2,813,413. The invention is directed to a mechanism for cutting ofI' the power for accelerating the extractor in the event undue unbalance is exhibited during the acceleration of the extractor.

In .the form of invention to which the invention has been adapted, the rotating extractor basket and the transmission therefor constitute an assembly which is supported upon a universal mount at the lower end of the assembly so that the assembly in effect constitutes an inverted pendulum, the upper end of which has a freedom of motion suitably damped, whereby unbalanced loads within the basket may rotate about the center of gravity, leaving the axis of the unit to gyrate. The amplitude of such gyration will be dependent upon the degree of unbalance.

The present invention is directed to the provision of mechanical linkage adapted to be actuated by the gyration of the non-rotating transmission mechanism of the unit, the linkage being connected to a cut-out switch for cutting off the power of the driving motor. The invention further has to do with the application of such linkage to the manually operated master switch of a timer Control commonly found on such machines, whereby the linkage may actuate such master switch upon excess gyration. It will therefore be seen that such master switch may serve as a manual cutoff which is in accordance with its intended use and may likewise serve as a cutoff acting in response to a pre-determined amount of gyration taking place in the wash unit during acceleration of the wash extractorv The above and other novel features of the invention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. it is expressly understood that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the 2 invention, reference being had for this purpose to the appended claims.

Inthe drawings, wherein like reference characters indi= cate like parts:

Figure 1 showns a side elevation of a washing machine of the type generally disclosed in the abovementioned application, parts thereof being broken away to show the control linkage;

Figure 2 is an enlarged fragmentary view of the timer mechanism and control linkage; and

Figure 3 is a fragmentary sectional view taken substantially on the line 3-3 of Figure 2.

In Figure 1 there is shown a frame having a base 10, support legs 12 and 14, and an external stationary splash tub .16 mounted within a cabinet structure 18. Supported on the base 10 is a wash unit comprising motordriven transmission drive mechanism 20 and 22 which support a rotatable extractor tub 24, the latter being located within the splash tub 16. It will be seen that the extractor tub has a tapered side wall 26 and overflow ports 28 for the purpose of discharging liquid centrifuged from the clothes when the extractor 24 rotates at a relatively high speed. The transmission mechanism 20 and 22 and more particularly the housings thereof which do not rotate are rigidly secured together by engaging bosses and the like such as 30, and the lower transmisa sion unit 20 is provided with an integral pedestal 32 mounted in a stationary socket 34, there being provided a resilient rubber cup 36 whereby the transmission unit and the tub 24 act as an inverted pendulum with universal movement.

It will be understood that the tub 24, when the load therein is balanced, will rotate about its axis A, which axis extends through the pedestal mount 32. Should there be an unbalanced load within the tub 24, such unbalanced load will tend to cause the axis A to gyrate, and by reason of resilient constraining forces and friction dampening members, such gyrations will be yieldingly constrained with the result that upon acceleration of the rotation speed of the extractor, the extractor will pass through what is known as the critical speed and thereafter tend to rotate about its rotational center of gravity, the axis of the basket gyrating substantially in a circular pattern, for example as is elliptically indicated by Circle B. If the unbalance is severe, the radius of gyration of the axis will increase, and if the unbalance be of a minor nature, the radius of gyration will be minimized.

It will be seen that there is a limited amount of clearance between the upper side wall 38 of the tub 24 and the stationary splash guard 16, and that if there is any danger of the radius of gyration being so great as to permit the tub 24 to come close to or strike the tub 16, the situation is unusual, and the power producing the acceleration of the extractor should be cut off to avoid possible danger.

Since there is a possibility of such severe gyrations, there is provided on the transmission, an arm 40 of a rigid character, which arm projects laterally and gener ally radially from the axis A to a point beyond the circumference of the splash tub 16. It will thus be seen that the outer end of the arm 40 will move up and down in response to gyration of the tub 24. Mounted in the cabinet of the washer beneath the inclined portion 42 of the cabinet deck in a clock-driven timer mechanism 44 which is adapted to control the sequence of operations of the machine during a complete wash cycle. Such timer is to all intents and purposes similar to that shown in Patent No. 2,313,064, granted March 9, 1943.

As shown in Figure 2, such timer comprises a manually settable shaft 46 which is adapted to be driven stepwise at slow speed by a clock motor 48. The shaft has afiixed' theretoone or more cams such as 50, which are socut as to control the various electrical circuits to automatically cause the washing machine to go through a complete cycle. The timer is also provided with a master control switch which is actuated by axial movement of the-shaft 46, it being seen in Figure 1 that such shaft is provided with a manual control knob 52 by which the timer can be angularly set or the shaft '46 axially moved. Such shaft has a pair of closely spaced annular grooves 54 and-56 in-which ride astationary yielding latch spring 58, it being understood that the shaft '46 may be moved from the position shown to a position axially downward by camming the latch spring 58 from the groove 54 into the groove'56. When the shaft '46 is moved'downwardly as set forth, the disc 60 mounted on the shaft 46 bears against a contact spring 62 and opens contacts 64, which contacts are in'the power supply line for the entire mechanism so that when the contacts 64 are open, the driving motor of the transmission is de-energized and further acceleration of the extractor tub 24 is terminated.

'It will thus appear that the contacts 64 are readily opened at any time that an operator desires to manually push the knob 52 axially downward to the position in which'the latch spring 58 rides in the annular groove 54, and that the machine may be restarted when the operatorlifts the shaft-46 to the position shown in Figure 2.

In order to cut oif the-power to the driver motor in response to severe gyrations during acceleration of the extractor'tub 24, there is provided on the timer a lever 66 fulcrumed'o-n the underside of the deck as at 68, such lever having an aperture 70 through which the shaft '46 extends. The lever bears against a collar 72 mounted on the shaft '46 which may be in the form of a split 'ring if desired. The free end 74 of the lever 66 is bent downwardly and is located substantially above the free end of thearm 40=mountedmpon the transmission unit. A link 76 extends between the arm 40 and the end of the lever 66, such linkhaving an upper L end 78 which is threaded through an aperature in the lever end 74, there being provided a rubber grommet 80 held in place by self-locking washers 84 and 86 on the rod end 78. The lower end of't'he rod 76 extends through a grommet 92 in the arm 40, 'the lower end of the rod extending well below the arm 40 and being provided with adjustable lock nuts 94, 96 and a resilient sleeve 98 threaded on the rod thereabove.

It will be seen in Figure 2 that a degree of clearance is provided as at 100 whereby the arm 40 may rock up and down in response to gyratory movement of the axis A of the extractor tub 24. Any degree of clearance at 109 may be selected by shifting the lock nuts 94 and 96 so that a safe limited degree-of gyratory movement may take place without in any way'afiecting movement of the link 76.

lt'will be seen that if the link 76 be moved downward, the lever 66 will be rocked downward, moving the shaft 46 of the timer downward to the off-position, opening the contacts 64 in the line circuit so that power to the driving motor will be cut off. Thus it will be seen that if the arm 40 rocks beyond the clearance 1 allowed, such rocking movement will move the link 76 downward and effect opening of the contacts 64. The resilient sleeve 98 serves the purpose of providing -a yielding abutment or cushion so that severe strains upon the link 76 and lever 66 will be avoided.

-It will thus be seen that a control is provided which requires no additional 'circuitiy or switches, and which comprises a minimum of parts, economical to produce and certain to operate in a safe, sure manner.

Although a single embodiment of the invention has been illustrated and described, it is to be understood that the invention is not limited thereto. A s various changes in the construction and arrangement maybe made without departing from the spirit of the invention, as will be apparent to those skilled in the art, reference will be had to the appendedclaims for a definition-of the-limitsof the invention.

What is claimed is:

l. A centrifugal extractor type washing machine comprising a frame, a wash unit mounted on said frame comprising, a transmission having a non-rotatable housing and-a rotatable centrifugal extractor -wash containing tub located above and'operably connected to said transmission, a motor for driving said transmission, a timer for controlling the operation of 'saidmotor'having'a master switch for cutting on power 'to said motor, said "Wash unit being yieldingly mounted upon said frame, whereby an unbalanced load in said tub may rotate about its center of gravity and said unit gyrate, linkage including an element secured to thenon-rotating housing and operably connected to said timer master switch for opening said master switch, said linkage including means providing limited lost motion whereby to rendersaid linkago'eifective to open said switch upon apredetermined degie'eof gyrationof said unit.

2. A centrifugal extractor type washing machine comprising a frame, a wash unit mounted on said frame'comprising, a transmission having a non-rotatable housing and a rotatable centrifugal extractor wash-containingtub located above and operablyconnected tosaid 'tran'smission, a motor for driving said transmission, a master switch mountedon said'frame for controllingthe-op'ration o'f said motor and for cutting oif power to said motor, s'aid'washunit being yieldingly mounted at its lower end upon-said frame, whereby an unbalanced load in saidtub mayrotate about its center of gravity, and said'unitg'yrate, an arm extending laterally from said unit at its lower end, means including a vertical link having a lost motion connection 'withsaid arm, and an operative connection With s'aidWnaster switch and responsive to a predetermined degree of gyration of the non-rotating housing of said unit for opening said master switch.

3. A centrifugal extractor type washing machine'comprising a frame, a wash unit mounted on said frame comprising a transmission having a non-rotatable'housing and a rotatable vertical axis centrifugal extractor wash containg tub located above and operably connected to said transmission, a motor for driving said transmission, a supporting universal mount for said unit on -'said frame located below said tub, a timer for controlling theoperation of said motor having an axially movable shaft and a master switch for cutting oif power to said motor actuated by axial movement of said shaft, means for yieldinglyconstraining said wash unit interconnecting between the non-rotating housing and frame for maintaining said unit upright with the tub axis vertical, whereby an unbalanced load in said tub may rotate substantially about its center of gravity, and said unit gyrate, means comprising an arm extending laterally from said axis, mounted on the non-rotatable housing of said unit, a lever on said timer adapted to axially move said shaft, and a extending generally parallel with said axis connecting said arm and lever.

4. A centrifugal extractor type washing machine comprising a transmission having a non-rotatable housing and a frame, a wash unit mounted on said frame comprising a rotatable vertical axis centrifugal extractor wash contain'ing tub located above and operably connected to said transmission, a motor for driving said transmission, a supporting universal mount for said unit on said frame located below said tub, a timer for controlling the operation of said motor having an axially movable shaft and a master switch for cutting off power to said motor actuated by axial movement of said shaft, means for yieldingly constraining said wash unit interconnecting between the non-rotating housing and frame for maintaining said unit upright with the tub axis vertical, whereby an unbalanced load in said tub may rotate substantially about its center of gravity, and said unit gyrate, linkage means comprising i an arm extending laterally from said axis mounted on the 6 References Cited in the file of this patent UNITED STATES PATENTS Watts June 6, 1939 Geldhof et a1. Sept. 16, 1952 Smith et al Oct. 17, 1952 

